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Molecular epidemiology of Campylobacter jejuni populations in dairy cattle, wildlife, and the environment in a farmland area.

Department of Medical Microbiology, School of Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Manchester M13 9WL, United Kingdom.
Applied and Environmental Microbiology (Impact Factor: 3.95). 07/2008; 74(16):5130-8. DOI: 10.1128/AEM.02198-07
Source: PubMed

ABSTRACT We describe a cross-sectional study of the molecular epidemiology of Campylobacter jejuni in a dairy farmland environment, with the aim of elucidating the dynamics of horizontal transmission of C. jejuni genotypes among sources in the area. A collection of 327 C. jejuni isolates from cattle, wildlife, and environmental sources in a 100-km(2) area of farmland in northwest England was characterized by multilocus sequence typing. A total of 91 sequence types and 18 clonal complexes were identified. Clonal complexes ST-21, ST-45, and ST-61, which have been frequently associated with human disease, were the most commonly recovered genotypes in this study. In addition, widely distributed genotypes as well as potentially host-associated genotypes have been identified, which suggests that both restricted and interconnecting pathways of transmission may be operating in the dairy farmland environment. In particular, the ST-61 complex and the ST-21 complex were significantly associated with cattle. In contrast, complex strains ST-45, ST-952, and ST-677 were isolated predominantly from wild birds, wild rabbits, and environmental water. A considerable number of novel sequence types have also been identified, which were unassigned to existing clonal complexes and were frequently isolated from wildlife and environmental sources. The segregated distribution of genotypes among samples from different sources suggests that their transmission to humans is perhaps via independent routes. Insight into the dynamics and interactions of C. jejuni populations between important animal reservoirs and their surrounding environment would improve the identification of sources of Campylobacter infection and the design of control strategies.

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    • "Several methods are available to perform molecular epidemiological studies and to carry out source attribution (Foley et al., 2009). Among these, multilocus sequence typing (MLST) has been used successfully to identify the link between C. jejuni isolated from different sources and human C. jejuni infection (Colles et al., 2003; Dingle et al., 2001; Kwan et al., 2008). "
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    ABSTRACT: The study aimed to investigate the prevalence of Campylobacter jejuni in not regularly monitored potential contamination sources such as free-living urban pigeons and crows, dogs, cats and urban environmental water and to assess the possible impact on the epidemiology of campylobacteriosis in children using Multilocus sequence typing (MLST). Campylobacter spp. were detected in 36.2% of faecal samples of free-living urban birds and in 40.4% of environmental water samples. A low prevalence of Campylobacter spp. was detected in dogs and cats, with 7.9% and 9.1%, respectively. Further identification of isolates revealed that environmental water and pet samples were mostly contaminated by other Campylobacter species than C. jejuni, whereas C. jejuni was the most prevalent species in faecal samples of free-living birds (35.4%). This species was the dominant cause of campylobacteriosis in children (91.5%). Apart from that, the diversity of C. jejuni MLST types in free-living birds and children was investigated. Clonal complex (CC) CC179 was predominant among free-living urban birds, however only two children isolates were assigned to this CC. One dog and one children isolate were assigned to the same clonal complex (CC48) and sequence type (ST) ST-918. The dominant two clonal complexes among children clinical isolates (CC353 and CC21) were not detected among C. jejuni strains isolated from environmental sources examined in this study. Since only two CCs were shared by environmental and children C. jejuni isolates and a high number of novel alleles and STs were found in C. jejuni isolated from free-living urban birds and environmental water, there is probably only a very limited link between urban environmental sources and campylobacteriosis in children, particularly in rather cold climatic conditions.
    Journal of Medical Microbiology 07/2014; 63(9):1205-13. DOI:10.1099/jmm.0.072892-0 · 2.27 Impact Factor
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    • "Recent studies using MLST have indicated that Campylobacter populations vary between host species and environmental niches (McCarthy et al. 2007) and that their lineages are associated with different host sources (Colles et al. 2003, 2008; Fearnhead et al. 2005; Miller et al. 2006). Further, the occurrence of rare allelic profiles, and their distribution among animal sources, has been reported in previous investigations using MLST (Kwan et al. 2008; Carter et al. 2009). Campylobacter spp. "
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    ABSTRACT: A repeated cross-sectional study was conducted to determine the prevalence of Campylobacter spp. and the population structure of C. jejuni in European starlings and ducks cohabiting multiple public access sites in an urban area of New Zealand. The country's geographical isolation and relatively recent history of introduction of wild bird species, including the European starling and mallard duck, create an ideal setting to explore the impact of geographical separation on the population biology of C. jejuni, as well as potential public health implications. A total of 716 starling and 720 duck fecal samples were collected and screened for C. jejuni over a 12 month period. This study combined molecular genotyping, population genetics and epidemiological modeling and revealed: (i) higher Campylobacter spp. isolation in starlings (46%) compared with ducks (30%), but similar isolation of C. jejuni in ducks (23%) and starlings (21%), (ii) significant associations between the isolation of Campylobacter spp. and host species, sampling location and time of year using logistic regression, (iii) evidence of population differentiation, as indicated by FST, and host-genotype association with clonal complexes CC ST-177 and CC ST-682 associated with starlings, and clonal complexes CC ST-1034, CC ST-692, and CC ST-1332 associated with ducks, and (iv) greater genetic diversity and genotype richness in ducks compared with starlings. These findings provide evidence that host-associated genotypes, such as the starling-associated ST-177 and ST-682, represent lineages that were introduced with the host species in the 19th century. The isolation of sequence types associated with human disease in New Zealand indicate that wild ducks and starlings need to be considered as a potential public health risk, particularly in urban areas. We applied molecular epidemiology and population genetics to obtain insights in to the population structure, host-species relationships, gene flow and evolution of Campylobacter jejuni in urban ducks and starlings.
    08/2013; 2(4). DOI:10.1002/mbo3.102
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    • "Campylobacter could spread from farms to the environment and could further spread to environmental reservoirs such as wild birds, which may facilitate their transmission from one farm to another (Waldenströ m et al., 2005). In a study in northwest England using multilocus sequence typing (MLST), most commonly recovered genotypes from dairy cattle, wildlife, and environmental sources were frequently associated with human disease (Kwan et al., 2008b). "
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    ABSTRACT: Abstract Dairy cattle serve as a potential source for Campylobacter infection in humans. Outbreaks associated with consumption of either Campylobacter contaminated raw milk or contaminated milk after treatment were previously recorded in the United States. Further, starlings have been implicated in the spread of bacterial pathogens among livestock. Here, we determined the prevalence, genotypic, and phenotypic properties of Campylobacter isolated from fecal samples of dairy cattle and starlings found on the same establishment in northeastern Ohio. Campylobacter were detected in 83 (36.6%) and 57 (50.4%) out of 227 dairy and 113 starling fecal samples, respectively. Specifically, 79 C. jejuni, five C. coli, and two other Campylobacter spp. were isolated from dairy feces, while all isolates from starlings (n=57) were C. jejuni. Our results showed that the prevalence of C. jejuni in birds was significantly (p<0.01) higher than that in dairy cattle. The pulsed-field gel electrophoresis analysis showed that C. jejuni were genotypically diverse and host restricted; however, there were several shared genotypes between dairy cattle and starling isolates. Likewise, many shared clonal complexes (CC) between dairy cattle and starlings were observed by multilocus sequence typing (MLST) analysis. As in humans, both in cattle and starlings, the CC 45 and CC 21 were the most frequently represented CCs. As previously reported, CC 177 and CC 682 were restricted to the bird isolates, while CC 42 was restricted to dairy cattle isolates. Further, two new sequence types (STs) were detected in C. jejuni from dairy cattle. Interestingly, cattle and starling C. jejuni showed high resistance to multiple antimicrobials, including ciprofloxacin, erythromycin, and gentamicin. In conclusion, our results highlight starlings as potential reservoirs for C. jejuni, and they may play an important role in the epidemiology of clinically important C. jejuni in dairy population.
    Foodborne Pathogens and Disease 12/2012; DOI:10.1089/fpd.2012.1293 · 2.09 Impact Factor